Refactor service injection to mogwais and gremlins

* Gremlins and mogwais no longer have default logger and randomizer
* The horde only injects logger and randomizer if not present (fixes #62)
* When a mogwai or a gremlin absolutely needs a service, and this service isn't present when it executes, it throws an appropriate exception
* Named anonymous function everywhere as is simplifies debugging
Merge pull request #64 from marmelab/null_default

[RFR] Refactor service injection to mogwais and gremlins
Improve attack duration explanation

Some users found it weird that the attack stopped after a few seconds
(#41). Increasing the default number of gremlins increases the attack
duration, and documenting how that works may hopefully prevent people
from wondering what happens.
fpsMogwai: use requestAnimationFrame shim for browser compatibility

Closes #50
Merge pull request #70 from marmelab/attack_duration

[RFR] Improve attack duration explanation
Merge pull request #71 from marmelab/request_animation_frame_shim

[RFR] fpsMogwai: use requestAnimationFrame shim for browser compatibility
Fix clickerGremlin click event not working for drag

Closes #63
Merge pull request #72 from marmelab/click_coordinates

Fix clickerGremlin click event not working for drag
Update minified version
typerGremlin: log Character instead of character code

Closes #58
Merge pull request #73 from marmelab/log_typer_key

typerGremlin: log Character instead of character code
Add bookmarklet

Closes #42
Merge pull request #74 from marmelab/bookmarklet

Add bookmarklet
Fix typo in bookmarklet link
Gremlins show action now uses a z-index of 2000

Gremlins action used default z-index, which made it invisible on
Bootstrap modals for instance. Using a higher z-index make the gramlins
actions visible on most situations. The max z-index of a bootstrap page
is 1050.

Closes #68
Merge pull request #75 from marmelab/action_z_index

Gremlins show action now uses a z-index of 2000
Update typer.js
Merge pull request #80 from onikiienko/patch-1

Mistake in documentation, file typer.js
mistake in doc
Merge pull request #81 from onikiienko/patch-2

mistake in doc